Automatic safety-guard



L. G. STABLES.

AUTOMATIC SAFETY GUARD.

APPLICATION man JULY 26. 1920.

1,400,835,, Patented Dec. 20, 1921.

2 SHEETSSHEET I- Migj p IN V EN TOR.

L. G. STABLES.

AUTOMATIC SAFETY GUARD.

APPLICATION FILED JULY 26, 1920.

1,400, 35; Patented Dec. 20, 1921.

2 SHEETS-SHEET 2- unwed LIN'I'ON STABLES, 01 LGS ANGELES, CALIFORNIA.

AUTOEIATIC SAFETY-GUARD.

Ll ll llfigfi.

Application filed July 26,

To all whom it may concern:

Be it known that I, Lin'ron Gnneonr S'rnnrns, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful improvements in Automatic Safety-Guards, described and claimed in the annexed specification.

My invention relates to improvements in automatic safety guards designed to be attached to machine tools, more particularly to those tools which have a manually oper ated period or cycle of operation such as punchpresses and the like; the objects being to provide a safety guard which will operate automatically before the machine operates and one in which the guard must travel fully into its operative position as such before the machine upon which it is installed can be thrown into operation; the device consisting of the novel features herein shown, described and claimed.

With reference to the drawings:

Figure l is a side elevation of a punch press showing the invention in a raised position and out of action.

2 is a side elevation of a punch press showing the invention held from being thrown into operation by a hand of operator.

Fig. 3 is a side elevation of a punch press with the invention in operative position as a guard.

Fig. 4: is a front elevation of punch press showing a front view of the invention in a position as shown in Fig. 1.

Fig. 5 is a side elevation of a punch press showing the invention operated by a hand lever and with a guard member and a treadlc removed.

The invention is herein shown attached to a punch press 1 comprising a frame carrying legs 2, 2, 21 table 3 and an upwar ly extending standard 4.

At the top of the standard is mounted the punch press mechanism consisting of a fly wheel 5, a shaft. 6, and punch element '2', the press being operated in the conventional manner.

The press has a releasing mechanism comprising a treadle 8, pivoted to one of the legs 2,'to which is pivotally attached a link 23 the upper end of the link being pivoted. to a rock arm 10 and from the rock arm 10 a second link 11 extends upwardly connecting with any of the conventional. means by which Specification of Letters Iatent.

serial No. 398,870.

such devices are released. On the table 3 is placed a die 12.

More specifically the present invention comprises a shell 13 positively mounted to the side of the frame 2.

ltotatably mounted within the shell is a bloclr 1 1 having a deep notch 15. Disposed at the top of the shell 13 is a guide 16 slidably carrying a pin 1'7, the pin being pivotally connected to the'rock arm 10 by a link 18. A

An arm 19 is'fixed across the face of the block 14: which extends along the side of the p ess toward thefront. i

An open frame 20, of screen or bars, is mounted upon the outer end of the arm 19, which is adapted to partly surround the die 12 and lay closelynbove the-table 3. The

frame orv guard 20. extends across the front of the die and the side opposite that which is carried by the arm 19 is carried by a second arm 21 which extends'backwardly and is pivotally connected to the standard 4 opposite the block 1 1.

The pins 19f and 19 extending from the side of the standard 1 form stops above and below the arm 19. p 1

An operating treadle 22 is pivoted to a leg 2 and is disposed above the treadle 8, it being connected to the arm 19 by a link 9. W here the link 9 connected with the treadle 22 it passes slidably through a block 2 1 which is fixed to the treadle and extends therebelow carrying spring 25 positioned screw seated upon the end of the link.

In the operation of the device, the press and safety guard being in a position as shown in Fig. l, the treadle'22 is pressed down by the foot of the operator thereby moving downwardly the guard 20 and rotating the bloclzlec The device is so adjusted that when the guard 20"is down upon the 19? the notch 15 is exactly under the pin 17 and the treadle 22 has been pressed down upon thetreadled. With a further pressure of the operator upon the treadle 22 the treadleB is pressed down thus rocking the arm 10 through the link 9 and the pin 17 is thereby enteredinto the notch 15 thus allowing the arm 10.;ton1ove enough to trip thepress by'means of the linl: 11.

Should the operators hand, as shown in Fig. 2, or other object be caught under the descending guard 20 and possibly upon the die the downward movement of the treadle Fatented lll ec. 1921.

between the block and nuts 26 which. are

22 would compress the spring 25 as it could not carry the guard down upon the stop and therefore the notch 15 would-not be rotated far enou 'h for the pin 17 to enter the notch 15- and t ough the operator might hear his weight upon the treadles 8 and 22 the pin 17 would simply rest upon the periphery of the block 14 and the press could not be tripped.

The same result would be had should the operator unintentionally put his foot directly upon the treadle 8.

On some devices such as paper cutting machines and the like, where the guard 20 could not be used to advantage, the remainder of the device maybe operated as a safety appliance in which case the block 14 could be rotated as shown in :Figs. 1, 2, 3 and 4 or by hand. as shown in Fig. 5.

In Fig. 5 itwill be noted the lever. 22 link 23 and guard 20are not shown and the arm 19 is formed into a handle, it being the intention that when "the, device is installed upon (such machines paper cutters and the like which are tripped by hand the operator would use one hand to. throw the block 14 into posi ion, and the other hand then to trip the, machine, thereby e1iminat- ,ing the necessity of the'guard' 20,"

'It is obvious that the. form ofthe block 14 and its mounting 13, might be changed and the connecting and operating mechanism of the invention altered in many ways to meet the especial requirements of the various machine tools upon which it might be installed and that other changes might be made in the structural detail of theinvention as shown without departing from the spirit and intent thereof as claimed.

Claims: V p

1. In an automatic safetyguard in combination, a'machine tool having a releasing mechanism and adapted to be released to travel through a certain cycle of operation, a guard element pivotally mounted upon. the tool and adaptedto swinginto and out of operative pos tion with each cycle of the tool,

a locking means mounted upon the pivotal amounting of said guard, means mounted upon'the releasing mechanism of said tool adapted to engage the locking means whereby thetool releasing mechanism can be operatedonly when the guard element is fully ,in operative position.

2. In combination in an automatic safety guard, a machine tool having a releasing mechanism and adapted to operate intermittently, a guard element pivotally mounted upon the'tool and adapted to swing into and out of operative position with each cycle of operation thereof, a groovedblock fixed to the pivotal mounting of the guard element notched block mounted within the casing and adapted to rotate with the swinging of the guard element, a guide positioned adj acent the casing, a pin slidably mounted in the guide and adapted to slide into the notch of the block, when the guard element is in operative position, a link connecting the pin with the'tool releasing mechanism and means for swinging the guard element into. and out of operative position.

4. An automatic safety guard comprising a. guard element, having a pivotal bearing, a casing adapted to surround the bearingand having a pin guide in its wall, a notched block fixed to the guard bearing and adapted to rotate therewith withinthe casing, a pin slidably mounted in the pin guideand adapted to slide freely into the notch of the block and to be connected at its outer end with a machine tool releasing mechanism, a treadle, a link connecting flexibly thetreadle with the guard element. I

5. In an automatic safety guard in combination, a machine tool having areleasing element to allow an operation of the tool,

only when the guard element is fully in operative position, a treadle, a link connecting with the guard element and having its lower end passing slidably through the treadle anda retractile spring positioned to bear against the treadle and against the lower end of the link whereby the treadle may he moved farther than the necessary distance to move the guard element into cp erative position.

In testimony whereof name to this specification.

L. GREGORY STAB ES.

1 have signed my 

